Function: fill-common-string-prefix

fill-common-string-prefix is a byte-compiled function defined in fill.el.gz.

Signature

(fill-common-string-prefix S1 S2)

Documentation

Return the longest common prefix of strings S1 and S2, or nil if none.

Source Code

;; Defined in /usr/src/emacs/lisp/textmodes/fill.el.gz
(defun fill-common-string-prefix (s1 s2)
  "Return the longest common prefix of strings S1 and S2, or nil if none."
  (let ((cmp (compare-strings s1 nil nil s2 nil nil)))
    (if (eq cmp t)
	s1
      (setq cmp (1- (abs cmp)))
      (unless (zerop cmp)
	(substring s1 0 cmp)))))